Construction of a new four leg roundabout on the A6003, allowing access to the west side of Corby via the A6003 and a minor road heading east towards Geddington. The A43 Corby Link Road generally runs north-east to south-west following the Kettering to Manton Railway line for approximately half its length. It links the existing A43 from Lincoln to the A6003 and the A14 and improves access from the east side of Corby to Kettering and the wider highway network.
Works to complete this scheme include:
- Construction of an in-situ concrete box culvert - 28m long, by 10.5m wide and 4.5m high taking the Harper’s Brook under the new A43 Corby Link Road.
- Complete re-construction & re-alignment of the A43 / A6116 (Stanion village) roundabout to permit the addition of a fifth arm for the new A43 dual carriageway.
- Over 800,000m3 earthworks, both topsoil and subsoil were undertaken between cuttings and embankments.
- Street lighting installation at both roundabouts.
- 19,000m of drainage and five balancing ponds.
- 110,000t of sub-base materials.
- 88,000t of surfacing materials.
Our in-house Traffic Management Team has liaised with Northamptonshire County Council and the Area 7 MAC AOne+ to co-ordinate all traffic management used on the scheme.
At the Southern Junction A6003 Rockingham Road and Geddington Road, off-peak lane closure and contra-flow systems were used to allow completion of the new roundabout and permanent southern tie ins.
A temporary diversion of Newton Road was constructed and closures of the existing side roads at Newton Road and Little Oakley Road were used consecutively to complete construction of the bridges and new sections of road over the dual carriageway including tie-ins at both extremities. TM was established on the side roads and maintained throughout the project. This included use of full-time four way traffic lights to control the plant crossing points.
We developed various innovative proposals during the construction phase, including:
- Reducing width of cuttings to maintain constant verge widths and improve mass balance on site. This gave cost savings of £29,000.
- Implementation of a ‘Performance’ based design (to IAN 73/06) for the pavement foundation, including CBR testing of formation, which permitted a decreased depth of sub-base. This produced cost savings of £56,000 and reduction in sub-base import by 10,300t.
- A number of surfacing options were introduced, including alternative pavement design for the new A43 and high friction surface course at junction approaches. Resultant reduction in bituminous surfacing depth totalled 55mm along the new dual carriageway. These changes saved £681,000 and reduced the number of lorry trips by 813 and C02 emissions by approximately 145t.
- Some of these cost savings have been reinvested to create a low maintenance central reserve for the new A43 dual carriageway (including surfacing to the whole area and introduction of V channels for surface water drainage and socketed concrete foundations for the vehicle restraint system) and provide additional re-surfacing works to 1.6Km of the existing A6003.
Working with the County Council the original 220,000m3 of surplus material has been reduced through the value engineering proposals and residual quantities have been used on site to create environmental and screening bunds. These proposals have saved around 21,000 lorry trips on the highway and the associated CO2 savings of approximately 1,100t.